Multicarrier modulation may be used in high-speed communication systems. Multicarrier modulation schemes include Discrete Multi-Tone (DMT) modulation and Orthogonal Frequency Division Multiplexing (OFDM) modulation. DMT modulation may be used in xDSL communication systems over copper in International Telecommunication Union (ITU) standards such as G.992.1 through G.992.5 as well as G.993.1, G.993.2, and G.993.5. DMT modulation is also being considered for G.fast, a standard that is in-progress. OFDM modulation may be used in radio-frequency wireless systems such as Digital Audio Broadcast systems or in wired systems, such as in ITU standard G.hn.
Multicarrier signals may experience large peak-to-average signal ratio (PAR) values, where PAR may be a ratio of an instantaneous peak power value to an average power value of a signal. Large PAR values present many challenges in designing multicarrier transceivers. A large PAR may demand large dynamic range for analog circuits and more precision for digital processing. Large dynamic range increases power consumption and cost of digital-to-analog converters (DACs), which may be needed in communication transceivers to convert digital signals into analog signals for transmission on physical media. Large dynamic range for line drivers (LDs) used for power amplification at a DAC output may demand higher voltage supplies and therefore higher power consumption. Consequently, it may be desirable to reduce PAR in multicarrier systems.